Matter is conserved


Chemical elements (and water) are stored in different forms across the biosphere

Energy flows, but matter is recycled























Each cycle includes aspects of Biology + Chemistry + Geology as elements move or are stored in the componenets of the biosphere

Importance of biogeochemical cycling: Nutrient limitation


Cycling = Transfer, transformation and storage


Biogeochemical cycles: Global


Nutrient cycles: Ecosystem


  • Entry of nutrients into system (IN)
    • fixation (bacteria)
    • weathering (rocks)
    • deposition (acid rain)


  • Internal transfer (recycling)
    • food webs
    • decomposition
    • inorganic - organic


  • Loss of nutrients from system (OUT)
    • gas loss, leaching, disturbance


  • Steady State and Succession….

Carbon cycle: Ecosystems


Carbon cycle: Global “sinks” and “sources” of carbon


Humans vs carbon sinks and storage…


Nitrogen cycle: Ecosystems


Nitrogen cycle: Ecosystems


Decomposition - Ecosystem internal recycling


Decomposition rate: Biomes (climate+microbes+material)



Nutrient transfer: Soil commmunity


Nitrogen cycle: Global


Primary productivity: Generation of biomass


Global net primary production


Global net primary production